CVE-2026-33356 | Meari MQTT broker missing per-device subscribe ACL

In Meari IoT Cloud MQTT Broker deployments running EMQX 4.x, any authenticated low-privilege account can subscribe to global wildcard topics and receive telemetry from devices the user does not own. The broker enforces publish restrictions but does not enforce equivalent subscribe authorization at per-device scope.

Published: 2026-05-11 Last update: 2026-05-13 Assigner: 44488dab-36db-4358-99f9-bc116477f914 Source: 44488dab-36db-4358-99f9-bc116477f914
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-33356 is rated Low Risk (33.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.03%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-33356

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-12 — 0.03% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33356

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.7 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.1 4.0 44488dab-36db-4358-99f9-bc116477f914

Weakness enumeration for CVE-2026-33356

GitHub Security Advisory for CVE-2026-33356

GHSA-2vfr-ch7v-7754 · Severity: high — In Meari IoT Cloud MQTT Broker deployments running EMQX 4.x, any authenticated low-privilege...

Affected software / configurations for CVE-2026-33356

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-33356

cvelogic Threat Intelligence